Vaping THC From Electronic Cigarettes

Inclusion * Age \>=21 years \<=70 years * Regular user of tobacco cigarettes (daily or most days) * Regular user of cannabis in any form (combusted or ingested) at least 5 days out of the month. * Positive for Tetrahydrocannabinol (THC) on screening toxicology test * Willing to abstain from tobacco smoking and all other combustible products (ex: cigars) for 12 hours prior to each outpatient hospital admission. * Willing to abstain from smoking/ingesting cannabis for 12 hours prior to each outpatient hospital admission. * Willing to abstain from using any kind of nicotine products for 12 hours prior to each outpatient hospital admission (ex: electronic cigarettes, nicotine replacement therapy). * Saliva cotinine ≥ 30 ng/mL and/or NicAlert of 6 * Healthy (based on limited physical examination and medical history collected during screening) * Heart rate \< 105 beats per minute (BPM) * Systolic Blood Pressure \< 160 and \> 90 (considered out of range if both machine and manual readings are above/below these thresholds) * Diastolic Blood Pressure \< 100 and \> 50 (considered out of range if both machine and manual readings are above/below these thresholds) * Body Mass Index ≤\<=38.0 Exclusion * Medical (The following unstable medical conditions): * Heart disease * Uncontrolled hypertension * Thyroid disease (okay if controlled with medication) * Diabetes * Hepatitis B or C or Liver disease * Glaucoma * Prostatic hypertrophy * History of paranoia after marijuana use * Psychiatri…